This research will seek to delineate the biochemical mechanisms in ocular epithelial tissues by which the intracellular concentrations of cyclic 3',5'-AMP (c-AMP) and cyclic 3',5'-GMP (c-GMP) are regulated in relation to PG synthesis. These investigations will use, primarily, isolated cell types obtained by enzymatic dissociation followed by density gradient centrifugation. These types of rabbit epithelial tissues will be examined: Those associated with a rich blood supply (pigmented and nonpigmented epithelial cells from ciliary process tissues, pigmented epithelial cells from the retina, epithelial cells from choroid plexus of the brain and isolated collecting tubules from the kidney cortex); those with no vascular association (endothelial and epithelial cells from the cornea); and those without blood supply or innervation (lens epithelial cells). Studies will continue using isolated cells prelabeled simultaneously with P33 and(C14)-dihomo-gamma-linolenic acid with subsequent isolation and counting of synthesized (P33)-c-AMP, (P33)-c-GMP and (C14)-prostaglandins (PGs) along with added tracer (H3)-c-AMP, (H3)-c-GMP and (H3)-PGs for recovery correction. Effects of added cyclic nucleotides of PGs upon endogenous levels will be examined as well as effects of oxygen tension, calcium levels, adrenergic drugs and cholinergic drugs. Interesting observations will be backed up by adenylate cylase and c-AMP phosphodiesterase assays. Some ocular epithelial tissues of rabbits with hereditary buphthalmia will also be examined. BIBLIOGRAPHIC REFERENCE: Jocoy, Marcus K. and Woods, W.D. "Effects of Antibiotics upon In Vitro Synthesis of c-AMP and Prostaglandins by Rabbit Ocular Epithelial Cells", presented at ARVO Meeting, April, 1975, Sarasota, Florida.